Medium pressure liquid chromatography MPLC

The synthesis of 6-hydroxy fluvastatin with M. rammaniana DSM 62752 gave high conversion (>95 %) in shake flask culture on 400 mL scale with 0.1 g L of fluvastatin as well as on 22 L scale in a Wave bioreactor-fed batch process at a final substrate concentration of 0.4 g L Instead of the partial purification by a second solid-phase extraction described above, 6-hydroxy fluvastatin can be obtained in high purity ( 95 %) by, for example, preparative medium-pressure liquid chromatography (MPLC) on RP18 silica gel. ... 

The term medium-pressure liquid chromatography (MPLC) covers a wide range of column diameters, different granulometry packing materials, different pressures, and a number of... 

Zogg, G.C., N dredy, Sz., and Sticher, O., Operating conditions in preparative medium pressure liquid chromatography (MPLC). II. Influence of solvent strength and flow rate of the mobile phase, capacity and dimensions of the column, J. Liq. Chromatogr., 12, 2049, 1989. 

Medium pressure liquid chromatography (MPLC) Lobar Li Chroprep Si 60 (40-63 pm) column (E.M. Merck)... 

It was found that root bark, containing egg cavities with feces, were avoided by the pine weevil H. abietis, so its feces were investigated in an attempt to find ways to control the weevil. After fractionation by medium-pressure liquid chromatography (MPLC) and analysis with gas chromatography-mass spectroscopy (GC-MS)... 

As expected, Me2CuLi-mediated reductive defluorination of 56 and subsequent meth-ylation with methyl iodide proceeded smoothly to give methylated product 57 in 96% yield. Regarding the stereoselectivity, a moderate Z-selectivity (Z E = 6.4 1) was observed for the olefin moiety, but the C-2-methylation proceeded in nonselective manner. Fortunately, two diastereomers were readily separable by medium-pressure liquid chromatography (MPLC) as shown in Scheme 10.18. Structural assignments were made based on the x-ray crystallographic analysis of (2S)-57. 

Reaction of benzaldehyde with Bu AlTeBu (typical procedure) In a flame-dried flask equipped with an Ar inlet and a rabber septum was placed n-BuTeTeBu-n (185 mg, 0.5 mmol). After BU2AIH (1 N in hexane, 1 mL) was added under Ar, the solution was stirred at 25°C for 1 h and then 2 mL of THF was added. The solution was cooled to -23°C and 2 mmol of benzaldehyde and 0.5 mL of EtjAlCl (1 N in hexane) were injected. The mixture was gradually warmed to 25°C, stirred for another 1 h and poured into saturated NH Cl solution. Products were extracted with EtjO (3X30 mL), dried over MgS04 and concentrated in vacuo. Medium pressure liquid chromatography (MPLC) of the residue gave pure Te-butyl tellurobenzoate in 71% yield (205 mg) in a hexane/Et20 (100 1) fraction. 

Dehydration of keto diol ( )-A derived from geraniol furnished furanone ( )-B. Its reduction with sodium borohydride yielded alcohol ( )-C as the major product. Treatment of ( )-C with the isocyanate derived from (/ )-l-(l-naphthyl)ethylamine gave a mixture of carbamates E and F. These were separable by medium-pressure liquid chromatography (MPLC), and E gave (+)-C, while F afforded (—)-C. 

Whether medium-pressure liquid chromatography (MPLC), counter-current chromatography (CCC), or preparative thin-layer chromatography (PTLC) was used. 

Purification can be accomplished with different chromatographic protocols, but in most cases, open-column chromatography is used. For example, during the separation process of cucurbitacins from Cucurbita andreana, Jayaprakasam et al. [12] employed a medium pressure liquid chromatography (MPLC) system, using silica gel and mixtures of chloroform-acetone as eluent. A similar protocol was used by Peters et al. [27] during the isolation of the cucurbitacins from Wilbrandia ebracteata, but in this case the elution was performed first with mixtures of petroleum ether / ethyl acetate and then with ethyl acetate / i-propanol. 

Rock samples were extracted using methylene chloride and a Soxhlet apparatus and the resulting extract was further fractionated by a semi-quantitative SARA separation. After asphaltenes were removed from the concentrated extract by precipitation with excess pentane, the pentane soluble portion of the sample was separated by medium-pressure liquid chromatography (MPLC) using a deactivated silica gel precolumn and an activated silica gel main column by eluting the saturate and aromatic hydrocarbon fractions from the activated silica column with hexane in the forward and back-flush modes respectively. Polar nonhydrocarbons were backflushed from the precolumn with methylene chloride-methanol. Carbon isotopes were done on a subset of hydrocarbon fractions at Coastal Sciences Labs, Austin, TX (Table 3). 

Other techniques that can be useful for the purification of protected peptide segments include normal-phase column chromatography on silica gel and medium-pressure liquid chromatography (MPLC) in both normal and reversed-phase modes [2,3]. 

Some special technological methods used are - normal pressure liquid chromatography (NPLC), - medium pressure liquid chromatography (MPLC), - high pressure (performance) liquid chromatography (HPLC), -distribution chromatography (e.g., DCCC, RLCC), -preparative thin layer chromatography (PTLC), - thin layer electrophoresis (TLE). 

Products were quite pure, for purification only standard flash chromatography or medium pressure liquid chromatography (MPLC) on silica gel were required. 

The importance of the clean particle size distribution varies depending on the type of chromatography being performed. In medium pressure liquid chromatography (MPLC), it is very important that silica or alumina particles of a very clean particle distribution be used (no fines and no large particles). Separation chemists need to remember that not all 40-63 pm silica gels are the same. Additionally, it is also very important to use an alumina or silica gel containing as little metal contamination as possible as demonstrated by Dynamic Adsorbents, Inc., media. 

MitteldruckflUssigkeits-chromatographie medium-pressure liquid chromatography (MPLC)... 

Arznei, Arzneimittel, Medizin medium-pressure liquid chromatography (MPLC) Mitteldruckflussigkeits-chromatographie medulla/pith/core Mark medullation Verkemung... 

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